I like my DXLOOP .. an interesting project with a higher gain compared to Alexloop .... i use 1,2m external diameter with Cellflex 1/2" (copper ext. diam 12,3mm) .. AlexLoop use 1m with RS217 (cooper ext diam7,35mm) ... the theoretical gains are higher (20m DXLOOP efficiency than the dipole positioned half-wave height: 66% -- 20m ALEXLOOP efficiency: 37,8%), (40m DXLOOP efficiency: 15,1% -- 20m ALEXLOOP efficiency: 5,1%) .... You can see my project http://www.qsl.net/ik5xct/ (http://www.qsl.net/ik5xct/) lookat DXLOOP or watch this video https://youtu.be/quADHsJWWjA (https://youtu.be/quADHsJWWjA) ... Anyway .. Alexloop is a good product but very expensive !!!
(http://www.qsl.net/ik5xct/Immagini/dxloop_ik5xct_diameter.jpg)
with me in SOTA QRP trekking expedition
(http://www.qsl.net/ik5xct/Immagini/sota_monte_matanna2015_ik5xct.jpg)